Heavy leaking 790 John Deere

[Twocansam]

How goes it I have a 790 John Deere filling the turn table with hydro . I have pulled the swing motor and had seals replaced already. I have checked filters and looked for blockages. I’m thinking the motor needs deeper work due to when re installed it leaked the same . The machine operates for about 15 minutes pukes all hydro fluid out of the turn table . 15 gallons 15 minutes . Any help would be appreciated thank you new member

 

[mg2361]

Welcome to HEF Twocansam!

Rotary manifold leaking?

 

[Vetech63]

I have pulled the swing motor and had seals replaced already.

I’m thinking the motor needs deeper work due to when re installed it leaked the same

Who did this work? How was a reseal job determined? Visually? A gallon a minute is a significant leak...........have you looked externally around the area there for maybe a hydraulic hose leak?

 

[Diesel Dave]

If it’s a straight 790, the air system pressurizing the hydraulic tank doesn’t help the leak situation either.
I also suspect the rotary manifold is the issue.

 

[excavator]

One quick way to tell if it is the swing motor, is there gear oil in the swing drive? If the shaft seal on the motor is bad it will push the gear oil out of the drive. More than likely it's the rotary manifold.

 

[361brock]

When my 792 did that it was the rotary manifold. That thing will have you swearing to remove with the steel lines connecting it. It came out the top with help of come a long. Hope that baby isn't heavily grooved, will need to weld and machined as they aren't being made anymore. Maybe salvage yard. Hope for it to be good enough just to reseal. You can pull up on air relief valve on top of hydraulic tank when you shut machine off to stop the oil from being forced onto turn table. good luck

Nick

 

[excavator]

Twocanscam, is this a straight 790, a 790D or an E series?